Treatment of hydrocarbon oils



Sept. 11, 1934. 5 5

TREATMENT OF HYDROCARBON OI-LS Filed Dec. 11, 1931 FURNACE INVENTOR JACOB BENJAMIN HEID W @441 flmw ATTORN Patented Sept. 11,1934

- 1,972,936 A TREATMENT OF HYDROCARBON OILS Jacob Benjamin Heid, Chicago, 111., assignor to Universal Qil Products Company, Chicago, 111., a corporation of South Dakota I Application December 11, 1931, Serial No. 580,353

- 2 Claims. .(Cl. 196-60) This invention relates to the treatment of hydrocarbon oils and refers more particularly to the heat treatment of the relatively heavy portions of crude petroleums to produce therefrom a variety of commercially valuable products.

More specifically the invention has reference to a process in which such relatively heavy portions of crude petroleums are converted by the cracking process into high yields of marketable gasoline andsubstantial amounts of asphalt with a minimum production of intermediate or gas oil fractions.

In one specific embodiment the invention comprises heating heavy hydrocarbon oils by indirect heat exchange with cracked vapors, subjecting such heated oil along 'with intermediate refluxes from theiractio'nator to conversion conditions of a I temperature and pressure, separating vapors from nonvaporized liquids," passing the vapors into an enlarged vaporizing or reaction zone, subjecting the total products from the-reaction zone to fractionation to produce overhead gasoline fractions which are cooled, condensed and collected and intermediate insufficiently converted refiuxes which are returned to the conversion zone for further treatment, subjecting the nonvaporized liquids from the-primary separation to reduced pressure distillation to produce vapors which are conductedto the final fractionator and residual liquids which are subjected to further distillation in the presence of steam and fixed process gases to produce asphalt.

Theexact' nature of the invention may be conveniently described by reference to the attached drawing which shows diagrammatically by the use of conventional figures an arrangement of elements in which it may be carried out.

Referring to the, drawing, heavy hydrocarbon oil mixtures such as straight run crude residua or suitable heavy overhead fractions from a primary crude, distillation may be supplied to the system through a line 1 containing a control valve 2 and be discharged by a feed pump 3 into a line 4 containing a control valve 5 leading to a vapor heat exchange coil 6 in the upper portion of a fractionator 26, the incoming oil thus receiving an-increment of heat from the vapors and assisting in their fractionation. A portion of the incoming relatively cold oil may be diverted around the heat exchanger coil through a branch line? and a valve 8' to allow further flexibility of operation, the oil thus diverted rejoining the portion that has passed through the coil and is leaving through line 7 containing control valve 8.

The refluxes from the bottom of fractionator 26,

which comprises hydrocarbon fractions of higher boiling point than is allowable in finished gasoline may be withdrawn from the fractionator through a line 9 containing a control valve 10 to a combined feed pump 11 which discharges in turn through a line 12 containing a control valve 13, line 12 joining with line 7 containing the indirectly preheated raw oil and the mixture passing from this point through line 14 containing control valve 15 to heating element 16' disposed to receive heat from a furnace 17. Heating element 16 may be of any suitable type of construction such as a coil made up of successive end-connected sectionsof pipe and may be designed to receive radiant heat at certain portions of its length and substantially only convectional heat in the remaining portions if desired, the furnace setting being suitably modified to produce this different method of heat transmission.

The temperature and pressure employed in heating element 16 will vary with a considerable number of factors such as the nature of the charging oil, the degree of conversion desired,

etc. so that only general ranges need be given, such as approximately 850 to 950 F., for temperature, and atmospheric to approximately 300'lbs. per square inch for pressure, the exact ,temperature and pressure range employed not being a feature of the invention.

The heated products may be discharged through a line 18' containing control valve 19 and enter a primary separator 20 which is preferably employed to effect relatively rapid separation of nonvaporized liquids from vaporized products, halt excessive decomposition of the former and retain larger amounts of liquids which are preferably utilized in a subsequent asphalt manufacturing step as will be presently more fully described. Thus separator 20 may have suspended therein a baflle 21 which represents any means ordevice which may be employed to mechanically throw out or trap the liquid particlesin the trans- .fer line products, these liquids being carried reactions to the desired point, and is also well insulated to conserve heat necessary for the endothermic conversion reactions.

Owing to the preliminary separation of nonvaporized liquids as already mentioned, there will be a minimum production of coke and heavy liquid residues in the reaction chamber 24 so that the process may be continued over a relatively long time interval without shutdown. The total products may be then discharged through a line 25' containing control valve 26' and enter a final fractionator 26 for their rectification to produce overhead gasoline fractions and intermediate refluxes which are further converted in the heating zone already described. The pressure employed in the fractionator is preferably considerably lower than that obtaining up to valve 26, though it still may be considerably superatmospheric and under certain conditions of operation may be practically the same as that obtaining in the preceding conversion zone, allowing for differential drop due to fluid friction inthe transfer lines. Line 25 also receives vapors and gases from the asphalt manufacturing unit from line 46 as will presently more fully appear. The vapors and gases from fractionator 26 follow the usual course of cooling to produce condensation of liquids and separation of gases, being passed through a line 27 containing a control valve 28, througha condenser 29 and thence through a line'30 containing a control valve 31 to a receiver 32. The fixed gases not utilized in the asphalt manufacturing unit may be withdrawn through a release line 33 containing a control valve 34 at a rate consistentwith the maintenance of a desired back pressure upon the preceding portions in the upper portion of the fractionator.-

Nonvaporized liquids which are mechanically separated in separator 20 are preferably passed) to an asphalt manufacturing unit through aline 43 containing control valve 44, this unit consisting in general of a reduced pressure flash chamber, 45 and a succeeding reducing or asphalt making still 53. Pressure is preferably-reduced to substantially atmospheric on passage of the liquid products through valve 44 which results in substantial further vaporization with elimination of fractions not readilyadapted to asphalt manufacture, these passing through line 46 containing control valve 4'? to join with line 25 and enter fractionator 26 as already mentioned. It will be obvious that the pressure employedin flash retort 45 must be at least as high as that in fractionator 26 to insure flow of gases and vapors in the proper direction and that if lower pressures are used in the asphalt producingv unit that a vapor pump will be required in line 46, though this is not'shown in the drawing.

Nonvaporized liquids from flash retort 45 may be conducted through a line 48 containing a control valve 49 to a pump 50 which discharges them through a line 51 containing a control valve 52 into the asphalt still 53in which distillation is continued until any desired consistency of asphalt is produced. The. reducing or thickening action may be assisted by the introduction of either saturated or superheated steam through a line '76 containing a control valve 77 and terminating in a spray 78. Distillation may be further assisted by the introduction of a portion of the process gases from receiver 32, these passing through a line 64 containing a control valve 65 to a blower or compressor 66 and thence through a line 67, a control valve 68 and a trap 69 for the removal of low boiling condensates which may separate from the gases, this separator 69 having a baflle '70 representing any means for securing tortuous flow and a draw line 71 containing control valve '72 for the removal of condensed liquids. The substantially dry gases then pass through line 73 containing control valve 74 and bubble through the liquid mass undergoing reduction tributing means 75.

The use of process gases in addition to producing a carrying effect upon the vapors given off in asphalt still 53 may be employed to control the temperature by the rate of admission so that undesirably high temperatures are avoided and the yield of asphalt is increased due to prevention. of further decomposition reactions. The gases and vapors evolved from the asphalt still are preferably passed through line 62 containing control valve 63 to the vapor space above the liquid level in flash retort 45 wherein they further assist in sweeping out heavy vapors and conveying them through line 46 to line 25 and thence to the final fractionator of the system.

It is preferred to operate the asphalt producing unit continuously in conjunction with the cracking unit, finished asphalt of any desired grade being continuously drawn through line 60 containing control valve 61 and pumped to storage.

A further control of the asphalt manufacture is provided by the use of a portion of the reflux 115 condensates from the fractionator of the system as cooling material, a line 54 containing control valve 55 being provided which permits the diversion of any necessary amount of these relatively cool refluxes either. through line 56 containing control valve 5'7 to line 43 leading from the bottom of separator 20 or through line 58 containing control valve 59 to line 51 leading to asphalt still 53.

A consideration of thanatur'e of the invention described in the preceding paragraphs will make it apparent to those skilled in the art to which it appertains that-it is adaptable to the processing 'of a widesvariety of charging stocks, particularly those residua resultingfrom the primary distil- 130 lation of asphaltic or semiasphaltic crudes, and that numerical data representing results of operations might be multiplied to a considerable degree. However, one characteristic example will serve to sufficiently indicate the commercial valu of the process.

In one instance a 26 .gravity Mid-Continent residuum may be processed in equipment similar to that shown in the drawing using a temperature of 930 F. at the exit of the heating element and 250 lbs. pressure per square inch in the separating and reaction zones, this pressure being reduced to slightly superatmospheric in the asphalt making and fractionating zones. The overall yields pro-,- duced in such as case may be as follows:

from a dis- I Per cent Gasoline, 55 gravity 425 end point 67 Asphalt, 40 penetration; 1 25 Fixed gases; a 1.56.

It will be observed that a high yield of gasoline is possible with substantially no formation of solid cokey residues, principally owing to the fact that the tendency to overcracking of the nonvaporized liquids from the heating element is minimized by effecting their immediate removal from the reaction zone. It will also be observed that. the gas loss is relatively low which constitutes an added advantage.

The foregoing specification and example, while serving to define the nature of the invention, indicate its broad scope and exemplify its operation, have been given for illustrative purposes only and are not to be considered in the light of imposing limitations upon the invention.

I claim as my invention: I

1. A process for converting heavy hydrocarbon oils into gasoline like distillates and asphalt comprising subjecting the oil to cracking conditions in a pressure distillation zone,.separately taking off-vapors and unvaporized oil from the pressure distillation zone, subjecting the vapors to a reaction time period adequate to form substantial quantities of gasoline, passing the unvaporized residue to a low pressure distillation zone, uniting vapors from the low pressure distillation zone with vapors taken off from the pressure distillation, subjecting the united vapors to fractionation and subsequent to fractionation to final condensation, collecting the resulting final distillate and separating the same from the incondensible gases, taking off the resulting residue from the low pressure distillation zone, and treating the same with substantially dry gases separated from said distillate and an oxidizing agent to form asphalt.

2. A process for converting heavy hydrocarbon oils into gasoline like distillates and asphalt comprising subjecting the oil to cracking conditions in a pressure distillation zone, separately taking off vapors and unvaporized oil from the pressure separating the same from the incondensiblegases, taking off the resulting residue from the low pressure distillation zone, treating the same with substantially dry gases separated from said distillate and an oxidizing agent to form asphalt,

and uniting volatilesdriven off during the treatment of the residue to form asphalt with the vapors evolved in the low pressure distillation zone.

JACOB BENJAMIN HEID. 

